text: import pytest
  from argparse import Namespace
  from Bio import Phylo
  from math import isclose
  
  from phykit.services.tree.internal_branch_stats import InternalBranchStats
  
  
  @pytest.fixture
  def args():
      kwargs = dict(tree="/some/path/to/file.tre", verbose=None)
      return Namespace(**kwargs)
  
  
  class TestLBScore(object):
      def test_init_sets_tree_file_path(self, args):
          t = InternalBranchStats(args)
          assert t.tree_file_path == args.tree
          assert t.output_file_path is None
  
      def test_read_file_reads_tree_file_path(self, mocker, args):
          mock_read = mocker.patch("phykit.services.tree.base.Phylo.read")
          t = InternalBranchStats(args)
          t.read_tree_file()
          mock_read.assert_called_with(args.tree, "newick")
  
      def test_calculate_internal_branch_stats(self, tree_simple, args):
          t = InternalBranchStats(args)
          internal_branch_lengths, stats = t.calculate_internal_branch_stats(tree_simple)
          assert isinstance(stats["mean"], float)
          assert isinstance(stats["median"], float)
          assert isinstance(stats["twenty_fifth"], float)
          assert isinstance(stats["seventy_fifth"], float)
          assert isinstance(stats["standard_deviation"], float)
          assert isinstance(stats["variance"], float)
          assert isinstance(stats["minimum"], float)
          assert isinstance(stats["maximum"], float)
          assert isclose(stats["mean"], 6.987232, rel_tol=0.001)
          assert isclose(stats["median"], 3.87382, rel_tol=0.001)
          assert isclose(stats["twenty_fifth"], 2.0946, rel_tol=0.001)
          assert isclose(stats["seventy_fifth"], 7.52973, rel_tol=0.001)
          assert isclose(stats["standard_deviation"], 8.011401268758792, rel_tol=0.001)
          assert isclose(stats["variance"], 64.18255028907, rel_tol=0.001)
          assert isclose(stats["minimum"], 0.846, rel_tol=0.001)
          assert isclose(stats["maximum"], 20.59201, rel_tol=0.001)
  